A nonvolatile semiconductor memory device comprises a plurality of sectors each having a plurality of memory cell arrays, a controller which responds to an address signal and a control signal to activate at least one of the sectors; and a plurality of data comparing circuits provided in the memory cell arrays, respectively, the data comparing circuits each which latches a write data to be written the respective memory cell arrays and compares the write data latched and a data read out from the respective memory cell arrays to produce a comparison result. The controller activates all of the sectors when the control signal has a first logic level regardless of levels of the address signal so that write data is written into the memory cell arrays of the sectors activated. The controller activates the sectors in sequence in response to changing levels of the address signal when the control signal has a second logic level to output the comparison results from the data comparing circuits in sequence.
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1. A nonvolatile semiconductor memory device comprising:
a plurality of sectors each having a plurality of memory arrays; a write circuit which simultaneously writes write data to said memory arrays of said sectors each; a write inspection circuit which conducts write inspection as to match/mismatch between data written to said memory cell arrays and said write data, and which outputs pass/fail decision data indicating whether or not writing to the memory cell arrays was successful; and an output circuit which outputs to the outside said pass/fail decision data that are arranged corresponding to each memory cell array in response to externally input address signals, wherein said write inspection circuit comprises a latch circuit which latches the pass/fail decision data for said memory cell array.
4. A semiconductor memory device comprising:
a first data line; and a first and a second memory sector coupled in common to said data line; said first memory sector including: a plurality of first memory cells; a first latch circuit coupled to said first data line to temporarily store a data that is transferred through said first data line to be written into a selected one of said first memory cells; and a first comparison circuit comparing the data stored into said first latch circuit with a data read out from the selected one of said first memory cells; said second memory sector including: a plurality of second memory cells; a second latch circuit coupled to said first data line to temporarily latch a data that is transferred through said first data line to be written into a selected one of said second memory cells; and a second comparison circuit comparing the data stored into said second latch circuit with a data read out from the selected one of said second memory cells. 3. A nonvolatile semiconductor memory device comprising:
a plurality of sectors each having a plurality of memory cell arrays; a controller which responds to an address signal and a control signal to activate at least one of said sectors; and a plurality of data comparing circuits provided in said memory cell arrays, respectively, said data comparing circuits each which latches a write data to be written the respective memory cell arrays and compares said write data latched and a data read out from the respective memory cell arrays to produce a comparison result; wherein said controller activates all of said sectors when said control signal has a first logic level regardless of levels of said address signal so that write data is written into said memory cell arrays of said sectors activated; said controller activates said sectors in sequence in response to changing levels of said address signal when said control signal has a second logic level to output the comparison results from said data comparing circuits in sequence. 11. A semiconductor memory device comprising:
a first memory sector including a plurality of first memory cells and a first inspection circuit producing a first signal indicative of whether or not a data write operation has been properly performed on a selected one of said first memory cells; a second memory sector including a plurality of second memory cells and a second inspection circuit producing a second signal indicative of whether or not a data write operation has been properly performed on a selected one of said second memory cells; a control circuit supplied with a first set of address signals and a second set of address signals, said control circuit responding to said first set of address signals to select one of said first and second memory sectors and responding to said second set of address signals to select at least one of the memory cells contained in the selected one of said first and second memory sectors, said control circuit being further supplied with a multi-program signal and selecting both of said first and second memory sectors irrespective of said first set of address signals when said multi-program signal takes an active level so that a data write operation is performed simultaneously on ones of said first and second memory cells selected by said second set of address signals, said control circuit responding to a change of said multi-program signal from said active level to an inactive level to have said first and second inspection circuits output said first signal and said second signal in sequence based on said first set of address signals.
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5. The device as claimed in
a second data line coupled to in common to said first and second comparison circuits, outputs of said first and second comparison circuits being transferred onto said second data line in sequence.
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1. Field of the Invention
The present invention relates to a semiconductor memory device, in particular to nonvolatile semiconductor memory device having an automatic multi-byte write function.
2. Description of the Related Art
In a nonvolatile semiconductor memory device shown in
A sense amplifier 4 and a write circuit 5 are connected in parallel to a bit line 1a of each memory cell array 1, and data are input to and output from the sense amplifier 4 and the write circuit 5 that are connected in parallel via an I/O buffer 6. Numerals 7 are a plurality of I/O terminals provided corresponding to the I/O buffers 6.
In the nonvolatile semiconductor memory device according to related art shown in
Now, when the multi-program is adopted in a nonvolatile semiconductor memory device as shown in
However, in the test mode it is necessary to apply a voltage of about 7V to the word lines of the memory cell arrays from an external power supply terminal that is not shown. It incurs an additional test time of 5 ns/address and results in a drawback of diluting the effect of reducing the test time.
In order to resolve the above problem possessed by the nonvolatile semiconductor memory device shown in
In
The nonvolatile semiconductor memory device according to related art shown in
The data control circuit 9 holds write data input from the I/O buffer 6, and outputs write data to the write circuit 5 at the time of writing. At write inspection, the data control circuit 9 compares data read from the sense amplifier 4 with the write data stored in it, and outputs data (data about the result of the write check for the memory cell array 1) about whether or not they match with each other (write pass) to the status circuit 10.
The status circuit 10, with the write inspection decision data as an input, outputs pass/fail decision data that indicate whether or not successful write to the memory cell array 1 was obtained, to the I/O terminal 7 and an operation control circuit 11.
The operation control circuit 11 completes the write operation to the memory cell array 1 when the write inspection decision data for the memory cell array 1 is a pass, and controls so as to repeat a rewrite and an inspection on the rewrite to the memory cell array 1 when the decision data is a fail.
Next, the operation of the nonvolatile semiconductor memory device shown in
When the write operation to the memory cell array 1 is started under the control of the operation control circuit 11 in this state, the write data held in the data control circuit 9 are written through the write circuit 5 to the memory cell in the sector S1, S2, . . . , Sn-1 or Sn selected by the input address signal.
Next, when the write inspection operation to the memory cell array 1 is started under the control of the operation control circuit 11, the data control circuit 9 reads the write inspection data for the memory cell array 1 through the sense amplifier 4, compares the write inspection data with the write data that are stored in the data control circuit 9, and outputs data (write inspection decision data for the memory cell array 1) as to whether or not they match (write pass) to the status circuit 10.
In the meantime, the status circuit 10, with the write inspection decision data for the memory cell array 1 output from the data control circuit 9 as an input, takes the logical product of the pass/fail decision data which indicate whether or not all the memory cell arrays 1 were successfully written, and when the write to all the memory cell arrays 1 is normally completed, outputs a signal to that effect to the I/O terminal 7.
When the write inspection decision data for the memory cell arrays 1 is a pass, the operation control circuit 11 completes the write operation to the memory cell array 1, resets all the operations, and sets the relevant components to a standby state for the next operation.
When the write inspection decision data indicates a fail, the operation control circuit 11 controls the memory cell array 1 to be subjected to a rewrite of data and an inspection of the rewriting.
However, in the case of automatic write operation for the nonvolatile semiconductor memory device according to the related art shown in
Moreover, for the verify mode, it is necessary to apply a voltage of about 7V to the word line of the memory cell array from the terminal of an external power supply, where the test time is Sns/address (write time) so that it results in a problem that a long time is wasted for the test.
It is the object of the present invention to provide a nonvolatile semiconductor memory device which is capable of suppressing the increase in write time due to the increase in the number of parallel write caused by the multiple write, and omitting analogous to the automatic write the time for write verify.
In order to achieve the above object, in a nonvolatile semiconductor memory device having memory cell region divided into a plurality of sectors, the nonvolatile semiconductor memory device according to the present invention makes it possible to write simultaneously write data to the memory cell arrays divided into the plurality of sectors, and output the inspection result of the write to the outside by scanning the address signals.
In a nonvolatile semiconductor memory device having memory cell arrays divided into a plurality of sectors, the nonvolatile semiconductor memory device according to this invention includes, write means for simultaneously writing write data to the memory cell arrays divided into the plurality of sectors, write inspection means for conducting write inspection as to match/mismatch between the data written to the memory cell array and the write data to be written to the memory cell array, and outputting pass/fail decision data indicating whether or not the memory cell array was successfully written, hold means for holding the pass/fail decision data for the memory cell array, and output means for outputting to the outside the pass/fail decision data arranged to correspond to each memory cell array in response to the externally input address signals.
The above and other objects, features and advantage of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
As shown in
The Y-selectors 2a, 2b each is connected to Y-select lines Y1 to Yn and receives the sector enable signal S0. In the Y-selector 2a, 2b each, the Y-select lines are connected to gates of the respective select transistors Yt1 to Ytn. The sector enable signal S0 is input to a gate of transistor 19a, 19b. The select transistor Yt1 to Ytn each has a current path between the respective bit line and the transistor 19a. The data control circuits 9a, 9b each has exclusive circuits 15a, 15b, latch circuits 16a, 16b, and gate circuits 17a, 17b. The gate circuits 17a, 17b each is connected to bit lines LB2, LB4 each. The bit lines LB2, LB4 are connected to the transistors 19a, 19b, respectively. The gate circuits 17a, 17b are connected to the latch circuits 16a, 16b, respectively, so that the latch circuits 16a, 16b latches data on the bit lines LB2, LB4 when control signal C1, C2 are activated, respectively. The latched data in the latch circuits 16a, 16b and the output from the sense amplifier 4a, 4b are input to exclusive circuits 15a, 15b, respectively. The output of the exclusive circuits 15a, 15b are connected to the bit lines LB1, LB3, respectively. The exclusive circuits 15a, 15b each can output in three states that are logic high and low levels and floating level. That is, when the signal S0 is a low level, the exclusive circuits 15a, 15b sets their output in a floating state. When the signal S0 is a high level, the exclusive circuits outputs logic high or logic low level as coincident or in-coincident result.
Exclusive circuits 15a, 15b and Y-select transistors 19a, 19b in the sectors MS2 to MS4 receives the sector enable signals S1 to S3, respectively in place of the signal S0.
The nonvolatile semiconductor memory device according to first embodiment of this invention shown in
The data control circuit 9 inputs write information for the memory cell array 1 via a sense amplifier 4, conducts write inspection as to match/mismatch with the write data to be written to the memory cell arrays 1 based on the received information, outputs the pass/fail decision data for the memory cell arrays 1.
Moreover, in order to output the pass/fail decision data to the outside as time series data corresponding to the memory cell arrays in response to externally input address signals, the memory cell region divided into a plurality of sectors are divided into two systems and a write circuit 5 is provided for each system, and write data are written simultaneously to all memory cell arrays 1 via a selected word line with the system as a unit.
Furthermore, the bit lines are sequentially activated by appropriately selecting time sequentially the Y selectors 2.
With this constitution, the memory device is controlled so as to input write data from the write circuit 5 simultaneously to all memory cell arrays with the system as a unit, by appropriately selecting the word lines and the bit lines time sequentially from the operation control circuit 11. In the meantime, the device externally outputs the pass/fail decision data for all memory cell arrays in sequence, in response to externally input address signals, by time sequentially selecting the Y selectors 2 based on the control from the operation control circuit 11.
Next, the operation of the nonvolatile semiconductor memory device according to the first embodiment of the present invention will be described with using FIG. 4. It is assumed that memory cells M11 of memory cell arrays 1a and 1b of sectors MS1 to MS4 each are selected and all of the memory cells M11 are written the data "1".
First, the memory device will be brought to test mode based on a command from the operation control circuit 11.
Subsequently, when the operation control circuit 11 produce a command so that the word line WL1 and the bit lines BL1 is selected by selecting the select line Y0 of the Y selectors 2a to 2h. At this time, Multi Program signal changes from high level to low level. The sector signals S0 to S3 are therefore activated so that all the sectors MS1 to MS4 are activated. Then, in response to a command, write data are inputted to terminals 7a, 7b and written simultaneously to all memory cells M11 of memory cell arrays 1a to 1h through the write circuits 5a, 5b and I/O buffers 6a, 6b. The write voltages for the memory cells are set by the write circuits 5a, 5b and the source voltage supply 12. circuits 18a, 18b. At that time, the control signals C1, C2 of a pulse signal are inputted to the transistors 17a, 17b and the write data are held by the latches 16a, 16b in the data control circuits 9a to 9h as shown at period between T1 and T2 in FIG. 4.
Next, the write inspection operation for the memory cells M11 is conducted. The XY decoders 11a, 11b sustain the address signals A0 to An-2 to keep selecting the word line WL1 and the select line Y1. All the memory cells M11 of memory cell arrays 1a to 1h are selected to be read out. Multi Program signal changes low level to high level.
At period between T2 and T3, the only signal S0 is activated and Data stored in the selected memory cells M11 in memory sector MS1 are read out and transfers into the data control circuits 9a, 9b through the transistors 19a, 19b and sense amplifiers 4a, 4b. In the data control circuits 9a, 9b, the exclusive circuits 15a and 15b compare the read out data from the memory cells M11 and the latched data in the latch 16a, 16b, respectively and outputs the match/mismatch result to the bit lines LB1, LB3. At that time, since the signals S1 to S3 are inactive, the exclusive circuits in the data control circuits 9c to 9h set their outputs in floating level. After the data control circuits 9a, 9b conduct write inspection to check whether the write data read out from the memory cell M11 is coincident with the latched data in the latch, the match/mismatch result data are transferred from the data control circuits 9a, 9b to the operation control circuit 11 via the I/O buffers 6a, 6b and the output lines GO1, GO2. It is noted that "T" in
When the operation control circuit 11 detects that the write to all memory cell arrays 1 do not complete normally, the operation control circuit 11 conducts to write the write data to the memory cell arrays failed until the write for all memory cell arrays 1a to 1h is completed normally.
It may be available to provide latch circuits to latch the output of the exclusive circuits 15a, 15b regarding the sectors MS1 to MS4 to hold the pass/fail decision data for the memory cell array 1a to 1h until the completion of the test mode.
When write for the memory cell arrays 1a to 1h is completed normally, the operation control circuit 11 outputs the sector address signals S0 to S3 into the logic circuit 3 to select sequentially sectors MS1 to MS4. The pass/fail decision data for the memory cell array 1a to 1h held in the data control circuits 9a to 9h are outputted to the outside from the I/O terminal 7.
In the above, the timing at which the operation control circuit 11 reads the pass/fail decision data for memory cell arrays is set at the time when the write to the memory cell arrays 1 is normally completed, but it may be set to be read in the order in which write to the memory cell array 1 is completed normally.
As in the above, according to this embodiment of the invention, the decision result of write inspection for the memory cell arrays is output to the outside by scanning the address signals. Accordingly, it is possible to suppress the increase in the write time due to the increase in the number of parallel writing caused by multiple write, or more specifically, due to the increase in the installation number of memory cell arrays divided into a plurality of sectors. Moreover, analogous to the automatic write, it is possible to omit the time for write verify by outputting the pass/fail decision data for the memory cell arrays to the outside in time sequential arrangement corresponding to the memory cell arrays. Furthermore, this method allows automatic multiple write for plural sectors, and has an advantage of reducing the test time for a flash memory or the like.
The nonvolatile semiconductor memory device shown in
Moreover, the data control circuits 9a to 9h each has latch means to hold the pass/fail decision data for the memory cell arrays 1a to 1h until the completion of the test mode.
Furthermore, analogous to the first embodiment, this memory device is constructed so as to output to the outside the pass/fail decision data for the memory cell arrays held in the data control circuits 9a to 9h as time sequential data arranged corresponding to the memory cell arrays 1a to 1h each by sequentially changing the address signals for respective sectors S1 to S2.
The structure of the memory device according to the second embodiment is explained with using FIG. 5. The explanation of the same structure with the memory device according to the first embodiment is omitted.
The input/output bus line GL0 is connected between the I/O buffer 6a and the data control circuits 30a, 30c, 30e and 30g. The input/output bus line GL1 is connected between the I/O buffer 6b and the data control circuits 30b, 30d, 30f and 30h. The write circuits 5a to 5h are connected between the data control circuits 30a to 30h and the Y-selectors 2a to 2h. The Y-selectors 2a to 2h each is connected to the respective select lines S0 to S3.
The structures of memory cell arrays 1a to 1h according to the second embodiment is substantially the same with those of memory cell arrays 1a to 1h according to the first embodiment. Moreover, the XY decoders 11a, 11b shown in
Next, the operation of the nonvolatile semiconductor memory device according to the second embodiment of the present invention will be described. First, the memory device is brought to the test mode based on a command from the operation control circuit 11.
Subsequently, the word line and the bit line are selected based on a command from the operation control circuit 11. In response to an operation command, write data are input from the external terminals 7a, 7b. The input data are written simultaneously to the corresponding memory cells of memory cell arrays 1a to 1h through respective write circuits. At that time, the write data are held in the latch circuits 16a each of the data control circuits 30a to 30h.
Next, the write inspection for the memory cell arrays 1a to 1h starts, the data control circuits 30a to 30h receive the data read out from the memory cell arrays 1a to 1h via the sense amplifiers 4a to 4h. Each of the circuits 30a to 30h conducts match/mismatch comparison between the data read out from the memory cells and the write data in the latch circuits 16a and outputs pass/fail decision data for the memory cell arrays 1a to 1h. Each of the circuits 30a holds the decision data in the latch circuit 50a.
When the write to all memory cell arrays do not complete normally, the operation control circuit 11 repeats data write to the failed memory cell arrays and read of write inspection data for these memory cell arrays once again, and stops the series of write operation upon normal completion of write operation for all memory cell arrays 1.
In this case, the data control circuits 30a to 30h holds the pass/fail decision data for the memory cell arrays until the completion of the test mode.
When the write to all the memory cell array is completed normally, the operation control circuit 11 outputs a sector address signal to the logic circuit 3, and the logic circuit 3 selects sequentially a plurality of Y selectors to read the pass/fail decision data for all memory cell arrays held in the data control circuit, and outputs the decision data to the outside from the I/O terminals 7a, 7b as time sequential data.
In the above, the timing at which the operation control circuit 11 reads the decision result of the write inspection for the memory cell arrays is set at the time when the write for all memory cell arrays is completed in normal fashion. However, the timing may be set in such a manner that it is read in the order normal write is completed for individual memory cell array.
As described in the above, In nonvolatile semiconductor memory devices having memory cell region divided into a plurality of sectors MS1, MS2, . . . , MSn-1 and MSn, the nonvolatile semiconductor memory devices according to the present invention shown in FIG. 1 and
More specifically, in nonvolatile semiconductor memory devices having memory cell region divided into a plurality of sectors MS1,MS2, . . . , MSn-1 and MSn, the nonvolatile semiconductor memory devices according to the present invention are provided with write means 5 for simultaneously writing write data to the memory cell arrays 1 divided into the plurality of sectors MS1, MS2, . . . , MSn-1 and MSn, write inspection means for conducting write inspection as to match/mismatch between the data written to the memory cell arrays 1 and the write data to be written to memory cell arrays 1, and for outputting pass/fail decision data indicating whether or not the memory cell arrays 1 are successfully written, hold means for holding the pass/fail decision data for the memory cell arrays 1, and output means 3 and 11 for outputting the pass/fail decision data arranged corresponding to each memory cell array, to the outside in response to externally input address signals. Here, in the case of
In the nonvolatile semiconductor memory device according to the present invention as shown in
In the nonvolatile semiconductor memory device according to the present invention as shown in
Moreover, in the nonvolatile semiconductor memory devices according to the invention as shown in FIG. 1 and
Besides, in the nonvolatile semiconductor memory devices of the invention as shown in FIG. 1 and
As described in the above, according to this invention in which a nonvolatile semiconductor memory device having memory cell region is divided into a plurality of sectors MS1, MS2, . . . , MSn-1 and MSn, write data are written simultaneously into the plurality of sectors MS1, MS2, . . . , MSn-1 and MSn, and the result of write inspection is output to the outside by scanning the address signals. Accordingly, it is possible to suppress the increase in the number of parallel writings due to multiple write, or more specifically, to suppress the increase in the write time due to the increase in the installation number of memory cell arrays that are divided into a plurality of sectors. Moreover, since the result of the write inspection can be output to the outside as arranged corresponding to the memory cell arrays similar to the multiple write, it is possible to omit the time for write verify.
Moreover, in a nonvolatile semiconductor memory device having memory cell region divided into a plurality of sectors MS1, MS2, . . . , MSn-1 and MSn, the present invention has the write means 5 for writing write data simultaneously into the plurality of sectors MS1, MS2, . . . , MSn-1 and MSn, the write inspection means for conducting write inspection as to match/mismatch between the data written to the memory cell arrays 1 and the write data to be written to the memory cell arrays 1, and outputting pass/fail decision data for the memory cell arrays 1, the hold means for holding the pass/fail data for the memory cell arrays 1, and means 3 and 11 for outputting to the outside the pass/fail decision data for the memory cell arrays 1 in response to the externally input address signals. Accordingly, in addition to obtaining the effect mentioned above, it is possible to conduct automatic multiple write for plural sectors by the application of the present invention without introducing a drastic change to the existing configuration, thereby reducing the test time for a flash memory or the like.
Moreover, the nonvolatile semiconductor memory device according to this invention may be configured, as shown in
Moreover, in the nonvolatile semiconductor memory devices according to this invention as shown in FIG. 1 and
Furthermore, in the nonvolatile semiconductor memory devices according to this invention as shown in FIG. 1 and
According to this invention, the decision result of the write inspection for the memory cell arrays is output to the outside by scanning the address signals. Accordingly, the increase in the write time due to the increase in the number of parallel writes caused by the multiple write, and more specifically, due to the increase in the installation number of the memory cell region that is divided into a plurality of sectors, can be suppressed, and analogous to the case of the automatic write, the time for write verify can be omitted by outputting to the outside the pass/fail decision data for the memory cell arrays in time sequential fashion arranged corresponding to the memory cell arrays.
It is apparent that the present invention is not limited to the above embodiments, but may be modified and changed without deviating from the scope and spirit of the invention.
Sekiguchi, Mitsuru, Ninomiya, Kazuhisa
Patent | Priority | Assignee | Title |
Patent | Priority | Assignee | Title |
6058495, | May 16 1996 | SAMSUNG ELECTRONICS CO , LTD | Multi-bit test circuit in semiconductor memory device and method thereof |
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